The advent of an efficient wide-field integral field spectrograph on an 8-m class telescope has revolutionized the study of the high redshift Universe, particularly when focusing on strongly lensed fields. Deep MUSE observations, conducted without any target preselection in these lensed fields and combined with space-based facilities like HST and JWST, have opened new avenues for the unprecedented identification of proto-globular clusters and very low metallicity star-forming complexes in the first Gyrs after the Big-Bang. I will review the pivotal role of MUSE as both a pathfinder and a game-changer in these studies. A significant fraction of information remains hidden in the datacubes, which have been the source of several key targets for JWST. I will present results from the MUSE deep lensed field on MACS J0416, including a series of discoveries and the latest findings emerging from JWST, which were initially inspired by MUSE observations.